Anatomy (Core B) While the Study Section acknowledged that the Scientific Core provides important support to all Projects, the core initially proposed employed a distinctly non-traditional format. In this revised application we have restructured the Scientific Core, based on a more traditional model. Dr. Basbaum, a dedicated senior level anatomist (25% effort), who could help in the development of sophisticated procedures needed for anatomical studies, and a technician, in the traditional (100% effort) to provide technical support, will be the Key Personnel. While a minimal supply budget is requested, for basic reagents and other supplies, more costly reagents will be acquired from individual components'budgets. Storage space for supplies for individual projects will be available in the Basbaum lab. Of note in this regard, Dr. Basbaum has recently moved to the Mission Bay campus (as part of the ongoing move of our neuroscience faculty to this new campus), providing him significant additional space than he had in his lab at the Parnassus campus site, a portion of which will be allocated to the Core. The shared antibody resource will also be physically located in the Basbaum lab, providing important reagents to all Pis. With respect to the use of confocal microscopes, all Pis have access to state-of-the-art confocal microscopes. Drs. Basbaum and Levine are on a funded multiuser equipment grant that has recently purchased a two-photon confocal that can image living cells, Dr. Messing has a confocal available to him at the Gallo Center and Dr. von Zastrow has access to two confocal microscopes in Genentech Hall, where his laboratory is located at the Mission bay campus, though none of the project Pis have the expertise in anatomical technique that will be provided by the Scientific Core. While all projects will have need for the Scientific Core, it is difficult to assign an exact percentage effort for the use of this Core by each project. Dr. Basbaum will assign the distribution of the time (percentage effort) of the technical personnel to support each of the projects. As noted by the review group, the Pis of this PPG proposal haye a long track record of working together, which we fully expect will include being able to accommodate each other's needs for the anatomist in the core. Finally, it should be noted that the role of Dr. Basbaum and the technical support person is to help develop the needed techniques and establish them in the individual component projects, not to perform all of the experiments in every project. Also, given the decreased number of projects, we expect that the anatomist will have adequate time and the ability to prioritize his/her effort for each project.